Friction-welding bosses are fastening elements to fasten parts to foamed or honeycomb materials/sandwich materials, as for example used in the automobile industry, in the boat-building industry, campervan-building industry, or airplane-building industry. Thereby, the friction-weld bosses are commonly made out of a high dense plastic and are mounted into the material by pressure and friction. By means of the pressure and friction heat is created, such that parts of the material, into which the friction-welding boss is mounted, is melted and bonds with the friction-welding boss. The friction-welding boss in this respect represents an ideal base for securely fasten components to foamed materials or honeycomb materials/sandwich materials. Friction-welding bosses are preferably flush-mounted into the material.
However, when the friction-welding bosses are flush-mounted into the different materials, the problem arises that frequently molten material emerges to the surface of the material between the friction-welding boss and the edge of the material and a bulge is created around the mounting place of the friction-welding boss. This bulge has to be removed in a separate step, in order to create a unitary surface structure, such that a component can be flush-mounted to the friction-welding boss. Furthermore, according to the characteristics of the cover layer of the material, it may be necessary in a first step to remove the cover layer, such that in a subsequent step the friction-welding boss can be mounted into the material beneath. However, therefore further tools are necessary, as for example a face cutter. Also, further steps are necessary, on the one side to change the tools and on the other side to correctly align the tools.